LAN Games

Hi,
I'm making a simple single-player game. Now, assume I've made the game, how would I go about making it available to play on LAN? (I'm not really bothered about making it playable across the world with people not on the same wi-fi)
So if anyone knows any way that I could get started or any libraries/APIs that could help I'd be thankful!
Edit:
I'm using Windows 8.1 and I'd like my game to be playable on other Windows OSs (7 and Vista if possible)